America's post-nuclear-attack chambers of Congress.

These unusual rooms on wheels are holdovers from the 1960s.

The secret city built by the Manhattan Project.

This nine-story building can be played like an instrument.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

A psychological self-portrait in the form of a giant, segmented head.

Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

This artificial archipelago was supposed to resemble a map of the world.

This Buddhist temple is home to the graves of the Japanese national legends, the 47 Ronin.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

This tremendous timepiece was once the largest cuckoo clock in the world.

A rare water-powered funicular, it uses a huge tank of water and gravity to do its work.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Scenic mount trashmore, Virginia Beach's most curious waterfront still has a couple of secrets.

Headquarters of the legendary clairvoyant's readings, spiritual hospital, and massage school.

One street divides a single town that stands in two U.S. states.

At 207 feet, one of the world's longest continuous escalators.

The skeletal white beams stand as a monument to religious dissent.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

This once-palatial plantation may have been the site where a draft of the Declaration of Independence was written.